Tunable interfacial properties of monolayer GeSb₂Te₄ on metal surfaces

Atomically thin monolayer GeSb 2 Te 4 holds promising prospects in non-volatile memory applications because of its high non-homogeneous crystallization rate. In GeSb 2 Te 4 -based devices, the interaction between GeSb 2 Te 4 and metals is crucial, as it affects the electronic properties. Herein, based on first-principles calculations, we investigate the interaction and Schottky barrier height of contacts formed by the combination of monolayer GeSb 2 Te 4 with various metals. It is found that the interfaces of GeSb 2 Te 4 with Pt, Pd, Ir and W exhibit strong interaction, characterized by large binding energies ranging from 1.394 to 1.015 eV, and the interfaces between GeSb 2 Te 4 and Cu, Ag and Au display weak interaction. For the seven contacts, Ag and W form Ohmic contacts with monolayer GeSb 2 Te 4 , while Cu, Au, Pd, Ir, and Pt form n-type Schottky contacts, with Schottky barrier heights ranging from 0.029 to 0.353 eV. The strong Fermi level pinning at GeSb 2 Te 4 -metal interface is observed with a pinning factor of 0.378. Additionally, altering the interfacial distance and optimizing the layers of GeSb 2 Te 4 enable a transition from Ohmic contact to Schottky contact. These findings provide crucial guidance for the design and optimization of electronic devices based on phase change materials like GeSb 2 Te 4 .